diff --git a/lib/extension-deflate-frame.c b/lib/extension-deflate-frame.c
index a3ff9f02..63ba6244 100644
--- a/lib/extension-deflate-frame.c
+++ b/lib/extension-deflate-frame.c
@@ -40,7 +40,10 @@ int lws_extension_callback_deflate_frame(
 			return 1;
 		}
 		n = deflateInit2(&conn->zs_out,
-				 DEFLATE_FRAME_COMPRESSION_LEVEL, Z_DEFLATED,
+				 (context->listen_port ?
+					DEFLATE_FRAME_COMPRESSION_LEVEL_SERVER :
+					DEFLATE_FRAME_COMPRESSION_LEVEL_CLIENT),
+				 Z_DEFLATED,
 				 -LWS_ZLIB_WINDOW_BITS, LWS_ZLIB_MEMLEVEL,
 				 Z_DEFAULT_STRATEGY);
 		if (n != Z_OK) {
diff --git a/lib/extension-deflate-frame.h b/lib/extension-deflate-frame.h
index 812af47e..00a4447a 100644
--- a/lib/extension-deflate-frame.h
+++ b/lib/extension-deflate-frame.h
@@ -1,7 +1,8 @@
 
 #include <zlib.h>
 
-#define DEFLATE_FRAME_COMPRESSION_LEVEL 1
+#define DEFLATE_FRAME_COMPRESSION_LEVEL_SERVER 1
+#define DEFLATE_FRAME_COMPRESSION_LEVEL_CLIENT Z_DEFAULT_COMPRESSION
 
 struct lws_ext_deflate_frame_conn {
 	z_stream zs_in;